We have paid between $20 (well, zero if you count the places that there was no one to pay) and $80. The setting and amenities seemed to bear no relation to the price. Highest has been $80 in Sag Harbor (a discount from $90 because it was after Labor Day) where the alternative was an absurdly expensive slip or anchor about a mile from town. Sag Harbor (in my opinion) has nothing to offer to justify that expense. $20 in Block Island because it was after Labor Day. Zero in Cuttyhunk because though we inquired, there was no one available to pay. As we work west on LIS the yacht clubs are getting $50. Would be anchoring more but 1) we have guests this week who are getting on and have trouble with the dinghy, and 2) the mooring fields, even though largely empty, usually occupy all the space that is close to anything. On a second or third visit through here I would certainly anchor out, but since it is our first we want to be closer to town.
Best deals were BI and Coecles Harbor where we took a free mooring at the Ram Head Inn. I think Sag Harbor and Nantucket ought to come up with at least some nicer bathrooms if they are hitting everyone for $80 and $75 respectively. I guess they get enough business that they don't have to lift a finger.
In Newport I was kicked off the mooring as they were preparing for the show, walked into the Newport Hotel and Marina and whined to the dockmaster a bit and got an alongside for $2/ft. Other places I called wanted $5 - $7/ft. Just for reference I was paying $6/ft PER MONTH for a very nicely protected double finger slip marina with nice facilities back on SF Bay. They supplied nicer weather, too.